Hans Richter

I’m ready for serious casting?

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9 hours ago, C.Read said:

Auto correct messed me up, I tried to say

So I'll shut up now and let y'all put your wisdom on me.

 

 

 

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Hi Colton, this looks and sounds so familiar to me:lol:. Believe me a take my first satisfaction regarding casting to -from making a big stock of ingots. (not using muffin forms but strong steel ones).

See, you still use the steel crucible (for Bronze:unsure:) remember the melting point from mild steel and Bronze are close together and some day you will find the whole batch back on the bottom of your furnace (like I did using the solid fuel forge and a cast iron crucible).

Regarding the moulds you absolutely have to take your time, be very accurate and patience:rolleyes:. Some people (like me in the beginning) are not so good in this. I take less attention to prepare the flask use of talcum powder as divider sieving the oil sand over the patterns etc….. If you’re not totally ‘Zen’ while preparing the flask you get bad results. 

Regarding the ash tree, after my opinion easy to cast if the body is slightly tapered to remove easy from the sand of the drag (bottom mould part). Only the wall thickness could be a problem (very thin because of pressed steel?) So my advice should be, to stack two ash tree’s over each other and sand them in. Then the wall of the final product will be thicker.

However its almost time for the next pay check so buy a decent crucible (empthy heat treat first), -get a good feeling for the liquid metal by casting ingots, polish the knuckle and put them on the wall like I did with my first imperfect bronze age heel axe as a humble reminder.

Btw -your material still looks a bit filthy, do you use flux (Borax/Salt) to collect impurity’s and do you remove all the slack and dross before casting (again a question of patience)

Hoop to be helpfull, Cheers, Hans

For more questions let me know or PM me.

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Also how are you degassing the melt before pouring?

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Hans - I am using borax. I just got a good skimmer shoo that should help. I put a little borax in at the beginning and the end. One problem I'm having is that when I try to put it in at the end the fire burns most of it up before I get it in to the crucible. Also I'm running a 8kg crucible but my foundry sashes it can take a 10. But if I make a bigger steel crucible that's taller than the graphite ones, I can melt more than that. I can use my current clay graphite crucible for brass going forward.

Thomas- I'm not using a degasser 

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Hi Colton, take the crucible out of the furnace and let them rest on a (two) hard firebricks add the flux to it on top of the liquid (don’t from the original sales recipient but a separated portion –added from the sales packaging I spoiled ones a 1/4lbs of Borax because the borax sticks together and all the contents fall in to the crucible). Let it melt again and stir it carefully -you will see the flux connect to the dirt and build a nice dross.

Be careful with Brass !!!! the oxidizing zinc is poisoning (zinc fever) here it’s very important to cover the surface of the liquid (avoiding free oxidizing by the flux) have a good ventilation and stay away from the fumes. Actually Brass casting is a 'sport' for some more advanced guy’s after enough practicing with ‘less’ dangerous aluminium, brass and copper (in this follow up).

Regarding degassing –till now I reach good results without degassing on the rough stuff, but Thomas is right I allways got some gas bubbles as an extra benefit.

For the next casts on lost wax moulds I will kiln them more properly and I will add some fine grinded charcoal chips to the liquid/flux (and carefully stir)  to degas and remove it with the dross before pouring.  

Especially for the more worn able and brittle parts (ash tree) this will be important.

Cheers, Hans

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Okay I was using the borax way wrong. I would get a punch with my gloves and sprinkle it in while the crucible was still in the foundry. 

As for brass, I melt outside with a respirator mask on. Plus I always try to stay up wind. I figure you can't be too safe. I need to get some fire bricks. The brick in the bottom of my foundry has broken in three different spots. 

My steel crucible sheds like a thin layer every time I fire it. It just has a a thin layer that is bubbled, looks like paint, but there is no pushing paint on the metal. I am going to make another steel crucible for the aluminum, so I can melt a lot. But the steel crucibles are heavy sands hard to pour so I'm going to weld up a pouring stand I saw in a YouTube video. For that crucible I'm going to drill holes at the top. Here is a drawing

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Scale; if you can get your fire to less oxidizing you can slow it way down but you will not escape it.

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Is that the metal flaking off? Is the wall thinning because of it?

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No the metal is not flaking off. It is Scaling Off and yes it is getting thinner.

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Short but good explanation. This ‘flakes’ are called mill scale. Every time you expose a piece of metal (steel, wrought iron) to heat and oxygen  (venturi oxygen rich flame of your furnace burner) you will get iron oxide (mill scale) and one day your piece of iron is gone. Same happens to pure un-coated steel if you expose it to rain (water) and air this elements also contain oxygen how loves to react with iron (Fe). Then you get iron oxide too, in this case it’s called rust^_^.

The dangerous white powder you get while melting brass is zinc oxide another form of oxidizing.

If you read other treats you will find discussions between our smiths brothers how to avoid too much oxidizing while heating up work pieces in gas forges because its affects the knives and other fancy stuff to.   

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On 7/26/2018 at 12:30 AM, Hans Richter said:

 quote removed

Thomas- I guess I'll need to look it up. So is the scale made from the metal melting in the foundry and then oxidizing?

 

Hand-held Definitely seen lots of the white power on the tools after my three burns of Brass. 

I will for sure have to look up ways to prevent it especially because I want to get into knife making.

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No it's not melting; just oxidizing---which happens faster when temperatures are elevated and when excess O2 is present.

As the zinc burns out of the brass it becomes harder to get a good pour, it's common to add small amounts of zinc to the melt to replace the stuff burned out. (Here in the USA you can use pennies made after around 1984 as they are copper plated zinc for fairly small pours. I  like to use the damaged ones I find on the street.)

I strongly suggest you read up on Metal Fume Fever and please read the safety III post over at anvilfire.com => iforge  for the worst possible result of it in a blacksmithing situation.

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Thank you! I will read up on it. I have already been using a respirator, goggles, gloves, and my leather welding apron.

 

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Colton

-like Thomas says, the to the burner /ember exposed outside of your crucible (steel body) will transfer after every heat from iron/steel to iron oxide. This happened to all smiths pieces (knife blades, chandeliers, s-hooks, bottle openers etc. p.p.). The floor around the anvil/power hammer of every blacksmith shop is covered with mill scale (mine to, even with all the German ‘Gründlichkeit’).  

So the smith cleans the glowing work piece with a wire brush before starting hammering to remove the mill scale to avoid to hammer in impurities. (Very funny if you give a forge demonstration and the surrounding lady’s ware nylon panty hoses)  

However a normal chemical reaction, which increase the mill scale if you use a gas burner with an oxygen rich flame (heavy blue cone). On the other hand important to get higher temperatures. If you use less oxygen you have problems with carbon monoxide witch is suffocation in confined spaces / badly ventilated rooms.  You (every blacksmith) have to find the right / save / and efficient setup.

I advise to join a local experienced smith brother with the ability to explain this basic knowledge to you like we do.

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Is your respirator good for metal fumes rather than just dust?  It takes a special version.  As welders often work with galvanized metal they often have issues with zinc burning off and I'm sure they make a good version to deal with it.

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Dust not fumes?????!!!!!!!   I would check with a good welding supply store as you are NOT sanding the stuff!

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Lisa made me a nice set of sheep knuckles from clay, just enough to cast a nice prehistoric game of knuckle dices from bronze.

After casting I will engrave the bronze bones with runes numbers and add them to my growing collection-_-.

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Very cool Hans, roll them bones! Ever play the "Royal game of Ur?" It's the oldest known "board" game, the direct ancestor of backgammon. The board is found scratched in tavern counter tops everywhere. It might have been as close to a universal human trade language as was back when cities were large villages.

Frosty The Lucky.

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That's the game! I play on a little different board but that's the game. There are lots of translations available. It's a great game for camping or picnicking you can draw the board on the table with charcoal or scratch it in the dirt and everybody can carve their bones/dice from sticks, colored pebbles are your markers. A piece of paper and a handful of change works as well as anything. 

I have a couple legs of lamb in the freezer and kept the feet, bones for stock and hooves for the dogs. I may have to clean some knuckle bones. 

The following is where I learned to play. How the rules were discovered is a darned interesting story. The game boards have been known for centuries, they're everywhere since before recorded history but "Dr? Finkel" who can just read cuneiform realized the rules were written down. Like I say cool story.

https://www.youtube.com/watch?v=WZskjLq040I

It's best to be Good and Lucky but if you can only be one, be LUCKY. 

Frosty The Lucky.

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Casted the Astragalus today according to Lisa’s pattern only 6 instead of 8 to complete two games-_-. Frosty - let me know when you are around, I like to invite you for a game or/and a pleasant stay in the ‘xxxx hole town of Belgium’.

Followed (not for the first time) ‘Herr’ Thomas Powers wise advice and degas the ladle for the first time with charcoal powder, add also some flux and an extra potion of tin to replace the burned out alloy. Thank you Mister TP the result is astonishing.

Now its waiting for the 35lbs crucible to have some serious work with the new melting furnace.

Colton CRead – please let us know what’s the progress with/on the ash trees I really like them.

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Deb will be thrilled to know we'll have someone to visit on our next visit to Belgium. Then again we don't visit the blank hole, Belgium. Are there more than one? -_-

Some of the trimmings will make nice pebble markers though it'd be nice to have another color for the opponent, tin maybe?

Is using nuts and bolts for gates a Belgium thing? I assume the sprue must be where the flask is singed but that's sure not how I learned to ram up a gang mold.

Came out nice even if it's not how I learned it 48+ years ago. :rolleyes:

Frosty The Lucky.

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Knuckle bones, Astralogus game are ready, also a Roman coat fibula.

Maybe creasy to spend almost 1 ½ days (except making pattern) to reproduce an old game (and many others items) without the intention to sell or commercialise them. However keeps me near to my family and ‘off the street’. Weight around 1,1lbs for the set of four. Lisa and their gothic/cosplay friends ask for smaller ones to hang on a neckless.

Next project will be a druid sickle or a bronze bell. Any other suggestions are welcome.

Cheers, Hans

   

At Frosty –got no other material for the gates at this moment and wont to avoid to scrape out the gates on the already fragile mould. Regarding the pebble markers I’m not familiar with this phenomenon and I don’t play golf ether-_-.

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